Trends in PM2.5 Concentration in Nagoya, Japan, from 2003 to 2018 and Impacts of PM2.5 Countermeasures

Atmosphere

Kazuo Osada¹  Kayo Ueda²  Shinji Wakamatsu³  Hironori Nakashima⁴  Makiko Yamagami⁴  Kunihiro Hisatsune⁴  Fumikazu Ikemori⁴ 

[1] Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601, Japan;Graduate School of Global Environmental Studies, Kyoto University, Kyoto 615-8540, Japan;Institute of Integrated Atmospheric Environment, Tokyo 112-0004, Japan;Nagoya City Institute for Environmental Sciences, Nagoya 457-0841, Japan;

关键词: PM_2.5;    elemental carbon;    organic carbon;    urban air pollution;    long-term trend;    pollution countermeasure;   

DOI  :  10.3390/atmos12050590

来源: DOAJ

【 摘 要 】

In Japan, various countermeasures have been undertaken to reduce the atmospheric concentration of fine particulate matter (PM_2.5). We evaluated the extent to which these countermeasures were effective in reducing PM_2.5 concentrations by analyzing the long-term concentration trends of the major components of PM_2.5 and their emissions in Nagoya City. PM_2.5 concentrations decreased by 53% over the 16-year period from fiscal years 2003 to 2018 in Nagoya City. Elemental carbon (EC) was the component of PM_2.5 with the greatest decrease in concentration over the 16 years, decreasing by 4.3 μg/m³, followed by SO₄²⁻ (3.0 μg/m³), organic carbon (OC) (2.0 μg/m³), NH₄⁺ (1.6 μg/m³), and NO₃⁻ (1.3 μg/m³). The decrease in EC concentration was found to be caused largely by the effect of diesel emission control. OC concentrations decreased because of the effects of volatile organic compound (VOC) emission regulations for stationary sources and reductions in VOCs emitted by vehicles and construction machinery. NO₃⁻ concentrations decreased alongside decreased contributions from vehicles, construction machinery, and stationary sources, in descending order of the magnitude of decrease. Although these findings identify some source control measures that have been effective in reducing PM_2.5, they also reveal the ineffectiveness of some recent countermeasures for various components, such as those targeting OC concentrations.

【 授权许可】

Unknown